SpudFiles

so if you where to have a single barrel piston shooter ,could you make a regulator and put it inside your air chamber and make a semi auto?

Uh, what?

Please take a step back and elaborate... slowly.

EDIT: Now I get you.

so, if you put an air regulator between the piston valve and chamber, it would not make a semi-auto gun. Regulator just lowers the pressure. Put a spring behind your piston and its semi-auto

Screw regulator and dual chambers, a spring loaded piston will do you nicely

i currently have a spring loaded piston , blow gun setup but even when i fire i cant get semi auto , it just dumps everthing in one go and ive shorten the button so i have to just tap the trigger to set it off would i have to do what wyz225 did with the blowgun mod?

You need to fill from the chamber and use a light hammer to open your blow gun, also you have pay close attention when making your valve. The barrel port and piston need to be very level so that it seals with the pressure of the spring alone i needed to buy a qev because i wouldn't be able to cut a straight with a drop saw. A hole for air to equalize from chamber to pilot is also required.


or you can just make it fuck load simpler and use a 3 way valve as you pilot/fill set up


edit:
i have a question tho about pressure reducing fittings. If i put a spring in the pilot of a qev and fill chamber side, would it essentially be a PRF(nic name)

The barrel port and piston need to be very level so that it seals with the pressure of the spring alone i needed to buy a qev because i wouldn't be able to cut a straight with a drop saw.

My Mouse Musket was built with no power tools. (love stick on sandpaper) The end of the barrel was made true by standing it on end on a flat level surface and again sanding it while rotating it until the wobble in the barrel due to an uneven end went away. The original pipe cap piston was trued the same way by slipping it on the end of a piece of pipe and truing it the same way.

The Mouse Musket barrel was trued on the sandpaper stuck to the plywood. Rotate and sand until it rotated with no visible wobble.


Super true power tools is not required to make a good fit. Only good technique is required. Later pistons were made on a drill press and machined true.

JSR:
That would have to be a really good piston seal if you were talking any serious pressures wouldnt it??
And also how does the air space behind the piston fill back up with pressure after it fires?

more_eggs wrote:That would have to be a really good piston seal if you were talking any serious pressures wouldnt it?

The great thing about piloted pistons is that the pressure keeps them shut, so the more pressure in the chamber, the more force keeping it sealed.

Herewith some examples of cast and solid rubber pistons that have served me well at up to 850 psi. The important thing especially at higher pressures is that the piston seat is wide enough to support the piston face without cutting into it.

And also how does the air space behind the piston fill back up with pressure after it fires?

The piston isn't 100% airtight so once the pilot is closed, air leaks past it and it fills up again, as with this prototype.

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Major Collins wrote:i currently have a spring loaded piston , blow gun setup but even when i fire i cant get semi auto , it just dumps everthing in one go and ive shorten the button so i have to just tap the trigger to set it off would i have to do what wyz225 did with the blowgun mod?

Its important that the pilot is momentary, a hammer valve like Brian did here or modded ball valve pilot are ideal ways of achieving this, from what I saw of wyz225's mod it should work well too.

Or you could just pilot into a small chamber and after resetting your valve, dump that volume.

This could be done with any 3 way valve.
I like this type because it is very efficient when it comes to air consumption.
You can finetune the dump-volume so it will fire just like you want it and not loose any more air.

Another way would be using this 3 way valve to fill/pilot.
Works like a charm but dumps the entire chamber volume each shot, so you'll need a bigger tank to fill the firing chamber after each shot.

Or keep it hooked up to a compressor.

But out of all the methods for achieving multi shot, I prefer a modified QEV and hammer valve.
As pressure goes down, opening the hammer valve becomes easier, resulting in a " deeper" shot.This somewhat compensates the loss of pressure so you get more consistent shots.

The basics behind my " Old Shatterhand" repeating musket.

Another way would be just using a hammer valve as you main valve and an autococking hammer ( in a tube) with some of the pressure used to blow back the cilindrical hammer...or use a barrel-airram to recock the hammer.
Have a vent in the barrel wich leads to an airram.

You could replace the basic hammer valve by a balanced one to get more flow etc..etc...

Lots of possibilities...

alright lets see , i think i will stick with my spring loaded piston valve and try to achieve semi automatic . but one question comes to mind ... what is the psi to how many shots you can get ratio? example 500 psi ,3 shot

theres no ratio that i now of, more volume+more psi=more shots if you keep the valve the same.

dam alright then thankyou for the info , but back to the regulator .... it just regulates air from one area to another...but doesnt force it in correct? eg 1000 psi chamber forcing 500 psi into a smaller chamber . It doesnt do that right? and is there a way i could do this without something like a compressor?

and i mean a air regulator like this type

http://cgi.ebay.com/ebaymotors/DeVILBIS ... -SPRAY-GUN
_W0QQcmdZViewItemQQhashZitem2eb3b607a3QQitemZ200583546787QQptZMotorsQ5fAutomotiveQ5fTools

Regulators don't "force" anything. They only allow a certain amount of pressure through. When the pressure in the second chamber rises above the pressure it is supposed to be regulated to, it will even vent it to the right pressure.

Not all regulators vent. Only ones regulating safe gas such as air are designed to vent. Gas regulators for welding do not vent and when they go bad are noted for rising pressure when you shut off your torch.

A regulator won't replace a compressor as noted above. It is simply a pressure controlled valve. When the outlet pressure rises the valve closes.